1. Field of the Invention
The present invention relates to thin-film thermoelectric cooling and heating devices for application in a broad range of applications from DNA genomic and proteomic chips, thermo-optical switching circuits, and infrared tags, and to the application of anisotropic heat spreaders to electro-holographic optical switching, thermocapillary and bubblejet optical switching, micro-strip delay lines for packet switching in cellular communication, and temperature control for probes in micro-surgery and bio-tissue analysis.
2. Description of the Background
Solid-state thermoelectric devices can improve the performance of electronic components, opto-electronic components and sensors. Today, thermoelectric devices based on bulk (˜1 mm thick) p-BixSb2−xTe3 and n-Bi2Te3−xSex alloyed materials are used in cooling applications. FIG. 1A is a schematic of a bulk device consisting of two thermoelectric materials 2a, 2b having an appropriate bias voltage for cooling at a Peltier contact 2c. FIG. 1B shows that the same device can be used for heating at the Peltier contact with an appropriate opposite bias voltage. Bulk devices present a cold surface or a hot surface existing across the entire top surface of the thermoelectric device. So far, bulk thermoelectric devices have not been made to selectively heat or cool local regions without heating or cooling adjacent areas because of their relatively large size (of each element) as well as lack of microelectronic type processing. As such, thermoelectric devices have not been employed in applications requiring selective heating or cooling.